Arrangement for improving the writing properties of fiber-point pens and the like



March 24, 1970 H. HARTMANN 3,502,417

ARRANGEMENT FOR IMPROVING THE WRITING PROPERTIES OF FIBER-POINT PENS ANDTHE LIKE Filed Nov. 5. 1967 3 Sheets-Sheet 1 March 24, 1970 H. HARTMANN3,502,417

ARRANGEMENT FOR IMPROVING THE WRITING PROPERTIES OF FIBERPOINT PENS ANDTHE LIKE Filed Nov. 5, 1967 3 Sheets-Sheet 2 /NVN r0? Heinrich A AWm/wH. HARTMANN March 24, 1970 ARRANGEMENT FOR IMPROVING THE WRITINGPROPERTIES OF FIBER-POINT PENS AND THE LIKE 3 Sheets-Sheet 5 Filed Nov.5. 1967 It'll Illlll'f llllllllll l United States Patent Office3,502,417 Patented Mar. 24, 1970 ABSTRACT OF THE DISCLOSURE Theinvention provides an improved fiber-point pen and the like with which apoint former containing a cavity is associated. The cavity comprises twodifferent coaxial coned sections of which the inner apical sectionserves to reshape the writing point of the writing utensil when the sameis not in use and when its protective cap is screwed on or oil.

BACKGROUND OF THE INVENTION This invention relates to a writing utensilcomprising a fiber bundle composed of individual synthetic fibers.

Well known fiber-point pens contain a pin-shaped rigid writing elementconsisting of a bundle of ultrafine fibers of nylon or the like embeddedin plastics. That is, the synthetic fibers are axially interconnectedwithin a holding means by a plastic bond. The synthetic fibers in thewriting point are shortened on the outer periphery relative to thefibers lying on the bundle axis. This bundle forms a conical writingpoint for conveying the ink by capillary action from a supply inside thepen through the writing point to the paper. Cavities which are locatedin the writing points to produce the capillary action cause the pointsto wear away. These writing points are compressible and thus lose theiroriginal generally conical shape after a relatively short period of use.Flats form on the writing point and cause the ink trace on the paper tobe irregular. The compression and deformation of the writing pointconstrict the cavities in its interior and thereby impede the regularHow of the ink. These and many other obvious disadvantages clearlyrestrict the usefulness of such pens.

SUMMARY OF THE INVENTION It is a primary object of this invention toovercome the disadvantages attendant the fiber pens of the prior art byproviding a means in combination therewith which can be used to reshapea deformed writing point comprised of a fiber bundle to its originalform for further use.

Another object of this invention is to reshape the writing pointconsisting of a bundle of fibers by using a means to uniformly maintainthe axial pressure on the fiber bundle during nonuse.

It is a still further object of the instant invention to provide a pointforming means attached to the interior of the protective cap of fiberpoint writing pen. This point forming means maintains an axial pressureuniformly on the fiber bundle during nonuse so that any deformity in thewriting point will be eliminated through reshaping.

It is still a further object of this invention to provide a protectivecap which is provided internally with a point forming member axiallyhaving a cone-shaped cavity directed towards the fiber bundle of thewriting point. The cone-shaped cavity includes a bigger side of whichfaces the writing point and has a shape corresponding to the shape ofthe undeformed writing point. The writing point is inserted into thecavity where it may be reformed under axial pressure.

Further embodiments of this invention provide for the protective cap tobe attached to the writing utensil itself.

The location of this protective cap is such that the writing point isunder axial pressure when the writing pen is not in use. One specificembodiment includes a mounting for the protective cap having thecone-shaped cavity axially movable through the use of a spring means.The point forming member disposed in the interior of the protective capis elastically supported against the inner side of the head of theprotective cap.

A further embodiment provides for at least one window-like opening inthe protective cap to observe the region of the point forming memberdisposed in the interior of the protective cap. Here the point formingmember is constructed of a clear transparent plastic material to providemeans for observing the writing point in contact with the said pointforming member.

BRIEF DESCRIPTION OF THE DRAWINGS Several embodiments of the inventionwill now be described by way of example and with reference to theaccompanying drawings, in which:

FIGS. 1 and 2 are two part sectional side views of point formers thatconstitute separate self-contained elements, each point former beingshown facing the writing element of a writing utensil that is to bereshaped;

FIGS. 3 to 5 are similar views showing point formers built intoprotective caps of writing utensils, each cap being shown facing thewriting point of the writing utensil to which the cap belongs;

FIG. 6 is an axial section of a different embodiment of a cap containinga point former;

FIG. 7 is a part sectional side view of a point former adapted to bescrewed into the rear end of a barrel;

FIG. 8 is an axial section of a writing utensil adapted for thereception of a replaceable ink storage cartridge insertable into thebarrel with a tight friction fit; and

FIG. 9 is an axial section of a writing utensil in which a replaceableink storage cartridge is positively located, the writing utensil havingits protective cap fitted with a point former.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 show a pointformer which has a body 1 of circular cross section made of plastics,metal or some other suitable hard material. At one end this body 1 isprovided with a central coned recess or cavity comprising two differentcoaxial coned sections, i.e., an inner apical section 2 and an outersection 3. The inner apical section 2 of the cavity has a cone surfacewhich roughly corresponds to the original cone shape of the writingpoint 8 of a writing utensil, or it may have a slightly more acute coneangle than that of a writing point that has not yet been worn anddeformed. The outer coned section 3 of the cavity opens outwardly andhas substantially the shape of a truncated cone having the same coneangle as the taper end 5 of the barrel 4 of the writing utensil. Ashoulder 6 is formed between the two coned sections 2 and 3 of thecavity.

In FIGS. 1 and 2 the cylindrical body 1 of the point former is extendedto form a shaft 7 which is provided with longitudinal fiutings or has asurface roughened in some other way to facilitate holding the pointformer for use. The writing utensil which is to be reshaped in theillustrated embodiments is a fiber point pen of conventional kindcomprising a barrel 4 with a conically tapering end 5. The writing point8 of a pin-shaped writing element projects from an axial bore in thetapering end 5 of the barrel. The writing element may in the knownmanner consist of a bundle of very fine filaments, such as nylon,embedded in a synthetic plastics matrix and thus forming a solid unit.The portion of the writing element which lies in the outlet bore at thetapering end 5 of the barrel 4 is embraced by a sleeve 9 of metal orplastics from which about 3 mm. of the writing point 8 freely project.

When the writing point 8 is deformed or so worn that it has lost itsoriginal shape, and thus, when used for writing. produces uneven lineswhich can no longer be controlled to be fine or thicker according to theangle at which the pen is held, then the end of the writing utensil withthe writing point 8 is pressed firmly into the cavity in the pointformer. The deformed point 8 of the writing element is thus pressed intoclose contact with the wall of the inner section 2 of the cavity,whereas the taper end 5 of the barrel 4 fits into the outer section 3 ofthe cavity. The pressure of the writing point 8 against the internalwall of the inner section 2 of the cavity reshapes the deformed writingpoint 8 which thus reassumes the shape which it possessed when it wasnew. The shaping effect of the point former can be improved byrepeatedly rotating the inserted writing point 8 several times in thecavity. The rotary movements smooth the freshly formed surface and pressprojecting nylon fibers back into the embedding matrix of the writingpoint 8.

1n FIG. 2 the surface of the inner section 2 is formed with undulationsextending in the direction of the cone axis and the crests of theundulations which project into the interior of the coned section 2 areprovided with a thin layer of emery 10. When the writing utensil isrotated inside the cavity of the point former or conversely when thelatter is rotated on the writing point 8 of the writing utensil, thelayer of emery has the effect of rubbing projecting ends of nylonfilaments and small particles of material off the coned surface of thewriting point 8 and of thereby smoothing down the surface to reshape theoriginal shape of the writing point 8. The cylindrical body 1 of thepoint former is provided with several, for

instance four, axial slit-shaped openings 11 placed in I quadrature andextending to the edge of the cavity. Particles of material that havebeen abraded by the layer of emery are discharged through theseslit-shaped openings 11.

Instead of being provided with a layer of emery 10 the crests of theundulations in the inner section 2 of the cavity may be shaped to formsmall cutting edges which act on the coned surface of the writing point8 in the same way as the layer of emery 10. A layer of emery 10 may alsobe applied to the internal concd surface of the section 2 when the sameis smooth.

In the embodiment illustrated in FIG. 3, the point former is resilientlymounted on a precompressed coil spring 17 inside a protective cap 12 ofthe writing utensil. The cylindrical body 1 containing the conedsections 2 and 3 of the cavity is rearwardly formed with asquaresectioned tang 13 which is slidably received into a correspondingsquare-scctioned blind hole 14 in a rear cover member 15 of theprotective cap 12 which simultaneously and in conventional manner servesfor securing a clip 16 when screwed into the rear end of the protectivecap 12. The precompressed coil spring 17 bears with one end against theinside surface of a ring 18 which carries the threads for securing thecover member 15 of the protective cap 12 and with the other end againstan external collar 19 on the cylindrical point former body 1. This coilspring 17 urges the point former forwards into contact with a sleeve 20firmly secured inside the protective cap 12. When the protective cap 12is pushed over the writing end of the writing utensil the writing point8 is received into the inner coned section 2 of the point former,whereas the taper end 5 of the barrel 4 is received resiliently into theouter section 3 of the cavity. The point former exerts a continuousreshaping effect whilst the utensil is not in use, as long as theprotective cap remains in position on the writing end of the barrel 4.The reshaping effect which in this instance may also be assisted by theprovision of a layer of emry 10 or by cutting elements, as in theembodiment described by reference to FIG. 2, is further improved if theprodtl tective cap 12 when being placed on, or removed from, the end ofthe barrel 4 is slightly rotated as is usually done. not only in thecase of protective screw caps, but also when threadless protective capsretained merely by friction are used.

The arrangement of the point former shown in FIG. 4 differs from that inFIG. 3 merely in that the precompressed coil spring 17 has been omittedand that the point former is rigidly mounted inside the protective cap12, i.e., that it is neither rotatable nor axially yieldable.

In the embodiment according to FIG. 5 the point former body 1 isrotatably located in a central bore 21 in the rear cover member 15 ofthe protective cap 12, but it cannot axially yield. Its rear extensionprojects from the outside of the cover member 15 and forms a twirlingknob 22. By twirling this knob when the protective cap 12 is inposition, the writing point 8 of the writing utensile can be reshaped tothe desired original cone form and at the same time its surfacesmoothed.

In FIG. 6 the body 1 of the point former, which may be either rigidlyfitted or yieldingly located into the protective cap 12, consists of aclear transparent plastics material. Openings resembling windows 23 arecut into the wall of the protective cap 12 on diametrically oppositesides in the region where the point former is fitted. These windows 23permit. the reshaping process to be observed for the purpose of checkingthat the writing point 8 is being properly shaped as desired.

The location of the point former inside the protective cup 12 of thewriting utensil is particularly convenient because the point 8 remainsin the reshaping cavity of the point former for longer periods and istherefore more effectively reshaped, and because the point former, beingpermanently fitted into the protective cap 12, cannot be lost.

In the embodiment illustrated in FIG. 7, the body 1 of the point formeris provided with an external screw thread 24 and removably screwed intoa female thread cut into the rear end 4a of the barrel 4. A knurled knob25 of a diameter larger than that of the body 1 of the point former islocated on the outside and forms an attractive rear termination of thebarrel 4 of the writing utensil. In all the described embodiments thepoint former also has the effect of helping to prevent the ink in thewriting point 8 from drying out.

In FIGS. 8 and 9 the writing utensil comprises a barrel in the form of ahollow plastics or metal shaft which is closed at one end and slightlytapered at the other, and an ink-containing cartridge replaceablyinserted into the barrel 30. The cartridge has a rigid or semirigid bodymade of plastics enclosing a supply of ink in an absorbent wad. Thelatter communicates with a pin-like writing element resembling a wickwhich may consist of a bundle of ultrafine filaments, such as nylonfilaments, embedded in a plastics matrix and forming an integral elementin the manner that is conventional in fiber point writing utensils. Theforward coned end of the pin-shaped writing element, which projectsabout 3 mm. from a central bore in the tapering forward portion 41 ofthe barrel 40, constitutes the writing point 8 of the pen. The portionof the Writing element which passes through the bore is enclosed in ametal or plastic sleeve 9. At the junction between the cylindricalportion and the tapering forward portion 41 of the cartridge 40 there isa coller 31 which should bear on the front edge of the barrel 30 whenthe cartridge has been correctly inserted, whereas a shoulder 32 formedat the junction between the cylindrical part of the cartridge 4t] and areduced end portion 40a bears against a corresponding shoulder insidethe barrel 30 (cf. FIG. 8).

The external diameter of the ink cartridge 40 fits into the interior ofthe barrel 30 in such a way that some force is needed to insert it intothe barrel 30, so that the ensuing friction will prevent the cartridgefrom rotating or from axially moving inside the barrel 30. A pointformer as hereinabove described may then be pressed over the writingpoint 8 and simultaneously rotated to restore the deformed and wornwriting point 8 to its original coned shape without causing thecartridge 40 to participate in the rotary motion.

In FIG. 9 the external diameter of the cylindrical shell of the inkcartridge 40 is a few millimeters less than the internal diameter of thebarrel 30 so that a slight annular clearance x remains between these twomembers. The ink cartridge 40 is frictionally held in place by aninternal bulge 33 in the rear end of the barrel 30 which prevents thecartridge 40 from accidentally being dislodged towards the forward endof the barrel 30 and from slipping out of the barrel 30 when the pen isbeing used. In order positively to prevent the ink cartridge 40 fromrotating inside the barrel 30 the reduced rear end of the cartridge 40is formed as a hexagon 40b and fits into a correspondingly shaped recessin the closed rear end of the barrel 30. The described positiveengagement of the cartridge 40 by the barrel 30 prevents the cartridgefrom being rotated when the writing point 8 is being reshaped bytwirling a point former applied to the writing point 8.

In the embodiment according to FIG. 9 the point former body 1 is shownnonrotatably and unmovably built into a protective cap 12 mounted on thebarrel with the point former containing the writing point 8. As alreadydescribed, the point former consists of plastics, metal or somealternative suitable hard materials and comprises a cylindrical bodywith a central cavity formed by two differently coned sections 2 and 3.The cone surface of the inner section 2 corresponds to the cone shape ofthe writing point 8 of the writing utensil when it is new, the objectbeing to restore the worn and deformed writing point 8 to this originalshape. The exposed edge of the sleeve 9 which embraces the writing point8 extends into the corner formed at the junction between the inner conedsection 2 and the outer coned section 3 of the cavity when the pointformer is applied to the writing point 8 for reshaping the same, i.e.,when the protective cap 12 is applied to or screwed onto the barrel 30of the pen.

The point former 1 is fixed in the protective cap 12 with a press fit orby attaching it to the rivet or screw required for securing a clip 16 tothe cap 12, or in some other suitable way in such a manner that when thecap 12 is pushed on the end of the barrel or pulled off the barrel andsimultaneously rotated for screwing it on or unscrewing it from athreaded barrel, the point former cannot rotate inside the cap 12. Thepoint former may otherwise be contrived as already described.

The invention may be embodied in other ways and comprise other forms ofconstruction than those that have been particularly described withreference to the accompanying drawings. More particularly, besides theabovedescribed embodiments shown in FIGS. 8 and 9 other possibilitiesare available for locating the replaceable ink cartridge inside thebarrel by friction and/ or by interengaging parts in such a way thatwhen the point former is rotated for shaping the writing point thecartridge will not participate in such rotation. The writing point andthe corresponding point former may also have a blunt truncated coneshape, the point being formed to receive a small terminal fiat insteadof a point and the edge of the flat being used for writing.

What is claimed is:

1. A fiber-point writing utensil comprising:

(a) means holding a bundle of axially interconnected, individualsynthetic fibers to form a conical writing point,

(b) a point forming member having a cone-shaped cavity with a largerforming surface to face the writing point,

(c) the larger forming surface has a shape corresponding to the shape ofthe undeformed writing point,

(d) the point forming member is mounted in a protective cap,

(e) the protective cap fits over the writing point and axial pressuremay be exerted on the writing point when the larger forming surface isjuxtaposed the writing point to reshape the writing point after it hasbeen deformed during use.

2. A fiber-point writing utensil as defined in claim 1 wherein theprotective cap is attachable over the writing point and fiber holdingmeans when the writing utensil is not in use and the bundle of fibersextend into a writing liquid storage cartridge for conveying writingliquid therefrom,

the bundle of fibers includes a plastic bond material to secure thefibers together and capillary channels located between the individualfibers and plastic bond material,

the synthetic fibers on the outer periphery are shortened relative tothe fibers on the bundle axis.

3. A fiber-point writing utensil as defined in claim 1 wherein the pointforming member is axially movable within the protective cap and acompression spring located between the point forming member and theinside of the protective cap to exert an axial pressure between thepoint forming member and the writing point.

4. A fiber-point writing utensil as defined in claim 3 wherein theprotective cap is attachable over the writing point and fiber holdingmeans when the writing utensil is not in use and the bundle of fibersextends into a writing liquid storage cartridge for conveying writingliquid therefrom,

the bundle of fibers includes a plastic bond material to secure thefibers together and capillary channels located between the individualfibers and plastic bond material,

the synthetic fibers on the outer periphery are shortened relative tothe fibers on the bundle axis.

5. A fiber-point writing utensil as defined in claim 1 wherein.

the point forming member is composed of a clear, transparent plasticmaterial and the protective cap includes a window means to observe thecontact between the point forming member and the writing point.

6. A fiber-point writing utensil as defined in claim 5 wherein theprotective cap is attachable over the writing point and fiber holdingmeans when the writing utensil is not in use and the bundle of fibersextend into a writing liquid storage cartridge for conveying writingliquid therefrom,

the bundle of fibers includes a plastic bond material to secure thefibers together and capillary channels located between the individualfibers and plastic bond material,

the synthetic fibers on the outer periphery are shortened relative tothe fibers on the bundle axis.

References Cited UNITED STATES PATENTS 631,000 8/1899 Symonds 401-269 X2,065,800 12/1936 Freeman 401-50 2,642,039 6/1953 Filak 401-51 2,782,4382/1957 Wittnebert et al 40l269 3,094,736 6/1963 Bunzl et a1 401-1983,274,975 9/1966 Dehlsen 401- X (Other references on following page) 7 83355,239 11/1967 Albrecht 401-198 422,577 4/1967 Switzerland. 3,365,7441/1968 Rigondaud 401198 LAWRENCE CHARLES, Primary Examiner FOREIGNPATENTS 307,198 3/1929 GreatBritain. 5 374,350 4/1923 Germany. 401-195US. C1.X.R.

